Google has reported a "sharp drop" in Gmail traffic today after Iran announced that it had blocked citizens' access to the webmail service.
Iran's telecoms provider said today that Gmail will be permanently blocked, and that a national email system will be rolled out shortly, according to reports in The Wall Street Journal.
The paper quotes an Iranian official as saying that the move is designed to boost local internet firms and build trust between the government and the people.
"We have heard from users in Iran that they are having trouble accessing Gmail. We can confirm a sharp drop in traffic, and we have looked at our own networks and found that they are working properly," said a Google spokesman in a statement.
"Whenever we encounter blocks in our services we try to resolve them as quickly as possible, because we strongly believe that people everywhere should have the ability to communicate freely online."
The Iranian government has been focusing more on the internet since protests erupted last June over alleged vote tampering. Protesters used services like Twitter to co-ordinate and share information, and the pro-government forces responded with denial-of-service attacks, including later against Twitter itself.
Twitter has been outspoken in its opposition to censorship. Co-founder Evan Williams used the World Economic Forum in Davos recently to commit to making Twitter difficult to censor.
The company also delayed a planned upgrade during the June protests to ensure that the service stayed up for the demonstrators.
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